1. Field of the Invention
This invention relates to selected aryl N,N'-bis cinnamamide compounds and their use as ultraviolet light stabilizers.
2. Description of the Prior Art
Ultraviolet (UV) radiation having wave lengths from about 280 to about 400 nm may cause the degradation of exposed organic matter such as plastics and will burn and/or induce tumors in human skin. To negate these undesirable actions, plastics and the like are protected by chemical additives called UV stabilizers and the human skin and hair is protected by cosmetics containing UV stabilizers (e.g. sunscreens).
To be viable for commercial applications, a UV stabilizer should preferably have a strong ultraviolet light absorptivity at wave lengths between 280 and 400 nm, be photostable by itself, be compatible with the substrate (e.g. plastic or cosmetic emulsion) in which it is used as an additive, be non-volatile at the high temperatures involved during incorporation and processing stages as well as during certain end uses, possess low color, be chemically inert, have low or no toxicity or skin sensitization/irritation properties, be non-mutagenic, and be stable to the environments experienced during its processing and application. Furthermore, for human sunscreen use, it is also desirable that the UV stabilizer be relatively insoluble in water.
Accordingly, it is an object of the present invention to provide a novel class of UV light stabilizer compounds.
A specific object of this invention is to provide a novel class of UV light stabilizer compounds which may be used to stabilize ultraviolet degradable organic compositions against deterioration resulting from the exposure to such UV radiation.
Another specific object is to provide a novel class of UV light stabilizer compounds which may be used in human cosmetic products such as sunscreens, hair dyes and hair tinting compositions to prevent or retard UV radiation from penetrating the human skin or hair.
These and other objects and features of the invention will be made apparent from the following more particular description of the invention.